1. Field of the Invention
The present invention relates to a diagnostic tool for repairing aircraft and to a method that uses this tool.
The field of the present invention is inspection and repair, if necessary, of aircraft. Throughout its operational life, an aircraft undergoes control inspections of varying degree in accordance with the manufacturer's instructions. Such inspections normally must make it possible to detect worn parts and damage suffered by the aircraft. When a worn part is detected or damage suffered is discovered, it is necessary to determine whether the aircraft must be grounded for replacement or repair of the part, or whether, on the other hand, it can take off again and be repaired later.
2. Discussion of the Background
At present, if damage is observed, a damage sheet describing the damage is filled out. Firstly, this sheet is filled out by the person who inspects the aircraft. It is then passed on to a technical team of the airline company operating the aircraft, which analyzes the damage, consults the Structural Repair Manual, known under the initials SRM, and can supplement the sheet.
At this point, a decision is made as to whether or not the damage is within the permissible airworthiness limits. If so, no repair is effected and the aircraft is permitted to take off again. In contrast, if the damage is too severe, the question arises of knowing which type of maintenance is to be performed: change of parts or repair? Repair methods for typical damage are provided in the repair manual SRM. If the discovered damage corresponds to such typical damage, the airline company then repairs the aircraft in accordance with the instructions of the manual SRM. In contrast, if the discovered damage is of unknown type, the manufacturer is consulted to assist its customer in repairing its aircraft.
Several problems crop up in this process of repairing an aircraft. Firstly, at the stage of filling out the damage sheet, it may very well be that two persons, such as two technicians of two different airline companies, will not fill out this sheet in the same manner for the same damage. Because of cultural differences, for example, the descriptions and questions printed on the damage sheets may not be understood and interpreted in the same way in all parts of the world. Furthermore, differences in organization exist within the airline companies. For this reason, the processing of a sheet may be entirely different from one company to another. In one company, for example, the sheet will be filled out completely by one and the same person, whereas in another company it will be filled out at different levels.
The first decision to be made when damage is discovered in an aircraft is to determine whether the aircraft must be grounded or whether it can continue its service. Prolonged ground time is very costly and should be avoided, but neither should an aircraft be flown if there is a risk of an in-flight breakdown. This first decision must therefore be made very quickly. Furthermore, if the aircraft is grounded, it is advisable to determine quickly what type of repair must be effected, in order to limit the duration of such ground time.